Khamenei out as Supreme Leader
Kalshi's rules said a leader leaving only through death pays the last traded price, not a dollar. Polymarket paid Yes in full.
The title said
Will Khamenei cease to be Supreme Leader of Iran by [date]?
The rules said
Kalshi's contract carried a death clause: if Khamenei left solely because he had died, the market would resolve on the last traded price before the death rather than at $1. Polymarket's version paid Yes if he lost the position for any length of time, by any route, on a consensus of credible reporting.
What happened
Khamenei was killed in US and Israeli strikes on 28 February 2026. Polymarket resolved Yes and paid Yes holders in full. Kalshi settled at the last traded price before the strike, which was far below a dollar. Kalshi then reimbursed all fees and covered traders' net losses out of its own pocket, so on that market nobody was left short — but only because the venue chose to.
The lesson
A 'death' or 'last traded price' clause changes what a Yes share is worth. It is one sentence deep in the rules and it decides everything.
What our card would have shown
- R4Unusual settlement clause, may not pay full value
Sources
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